Practice!

Sample Problem

Find the inverse of.

Inverse of A=

Solution

Find the inverse of by adjoining the identity matrix:

Use row operations to obtain:

Switch E3 withE1

E3=E3-3E1

E3=E3/8

E2=E2/2

E2=E2+1/2E­3

E1=E1+3E3

=

Check:

AA-1=